Driving mechanism.



F. H. VAN HOUTEN.

DRIVING MECHANISM.

APPLICATION man mum. 1913.

Panama May 18, 1915.

To all whom it may concern Be it known that I, FRANK H. Van HOUTEN, acitizen of the United States, residing at F ishkill on the Hudson, inthe county of Dutchess and State of New York,

have invented certain new and useful Improvements in Driving Mechanlsm;'and I do hereby declare the following to be a full, clear, and exactdescription of the same, reference being had to the accompanylngdrawings, forming part of this specification, and to the figures andletters of reference marked thereon.

This invention relates to driving mechanism or mechanism fortransmitting power from one moving part to another, the invention beingparticularly designed for efi'ecting the rotation of a series of pairsof wheels or rollers, such, for example, as are employed for operatingthe horizontal belts in adough proofing cabinet, where the surface speedof the several parts is to. be maintained substantially uniform.

One object of the invention is to provide a driving mechanism with whichany number of pairs of wheels may be operatedat a uniform speed withouttransmitting the power through intermediate gear wheels whereby theeffect of cumulative lost motion is obviated and whereby the drivenparts may be individually of light and small proportions.

Referring to the accompanying drawings,-Figure 1 is an elevation showingtwo pairs of wheels with their driving mechanism arranged in accordancewith the present invention, the supporting frame, etc., being entirelyomitted. Fig. 2 is a detail elevation on an enlarged scale of a smallsection of the flexible rack which constitutes the member fortransmitting motion to and between successive pairs of wheels. Fig. 3-

'is a plan of the section of flexible rack shown in Fig. 2. Figs. 4 and5 are views of two of the links of which the flexible rack is composed.Fig. 6 is a detail of one of the pivot pins or pintles for joining thelinks.

Like letters of reference in the several figures indicate the sameparts.

The driving mechanism of the present invention embodies essentially aflexible rack which is distinguished from a sprocket chain in that it isincompetent for cooperation with a sprocket wheel around which itSpecification of Letters Patent.

Application filed June 8, 1918. Serial No. 772,441.

Patented May 18, 1915.

may pass and is only adapted for transmitting power in a straight line.words, the links of which the flexible rack is composed are providedwith rack teeth, the operative faces of which cannot be made to conformwith the operative faces of the sprocket wheel to effect an economicaland effective transmission of power to or from said wheel. This flexiblerack is illustrated in the accom anying drawings as composed of a series0 I relatively thin H-shaped links A, Fig. 4, the spaces between thelegs of the tooth extensions a being cut to conform to standard geartooth practice, and the ends of the links are formed at anglescorresponding to the angles of the surface between the tooth extensionsa whereby when the links are assembled, as shown in Figs. 1 and 2. andextended in a straight line, there is formed a true rack bar which,however, is flexible inasmuch as the several links are assembled, asshown in Fig. 3, on transverse pivot pins or pintles B, Fig. 6, the axesbeing coincident with the intersection of the axes of the toothextensions and the longitudinal axes of the links, as will be readilyunderstood from an inspection of Fig. 4.

By reason of the spaces between the ends of adjacent links lying end toend, the flexible rack may be bent on a comparatively short radius and'it is conveniently supported in operative position by an idler sheaveor pulley C, Fig. 1, on which it is freely suspended, the lower part ofthe. rack forming a pendent loop below the sheave.

The pairs of wheels or rollers, one pair of which may be drivers, arearranged on opposite sides of one reach of the rack. Thus, as shown inFig. 1-, each pair of wheels is composed of a large gear wheel D and asmall gear wheel or pinion E arranged with In other their teeth in meshwith the oppositely probar is maintained in its proper engagement 7 withthe wheels by forming the pmions or small gear wheels E of slightly lessthickness than the thickness of the rack bar and in forming the edgelinks of the rack bar which project toward the smaller gear wheels solidor without the intermediate recesses as shown, for example, at a 1nFigs.

if followed on both sides of the rack bar would be a disadvantage,inasmuch as it often becomes desirable to separate the rack bar andwheels with which it is in mesh. Such a construction would require thecomplete disassembling of the machine. With the construction shown,however, any pair of wheels may be disconnected by simply loosening oneof the wheels D, for example, on its shaft and shifting the samelongitudinally of its axis out of mesh with the rack bar, whereupon therack bar may be deflected away from the wheel E and the latterdisconnected from its shaft and removed.

In assembling the several links of which the rack bar is composed, thepivots or pintles B are preferably headed up so as to clamp the edgelinks, Fig. 5, whereby each pair of edge links is formed into a rigidstructure, the intermediate links being pivotally connected therewith bybeing journaled on the pintles B. This construction prevents edgewisedistortion of the rack 'bar and makes a more rigid and effectivestructure.

The formation of the edge links without the tooth recesses on one side'of the rack bar, as shown in Fig. 5, not only retains the rack barpositively in engagement with the sprocket wheels, but the edges ofthese edge links serve a useful function in supporting the rack bar onits carrying sheave or idler, for as will-be seen by an inspection ofFig.

1, the edge links will practically support V the rack bar on the sheave.0, thereby protecting the face of the latter from wear by the sharpedges of the intermediate teeth and-also preserves the form of thelatter so that their efficiency will not be impaired by contact and wearagainst the surface of the sheave.

It will be understood that one of the pairs of rollers D and E, as, forexample, the lowermost pair in Fig. 1,.are driven from any suitablesource of power and that any desired number of pairs of rollerscorresponding thereto may be,located above the same and in ,linetherewith and with each other below the rack carrying sheave C. Thepower is thus transmitted directly to each pair of rollers, therebyavoiding lost motion such as would occur were a series of intermeshinggear wheels employed. Furthermore it is found that power transmittedthrough a flexible rack in this way is practically subjected to no lossthrough. the gearing itself and, therefore, manypairs of rollers may bedriven by a comparatively light motor.

Each pair of wheels may, of course, be made light and of smallproportions, the

.strength required of each pair being only suflicient to resist thestrains incident to its own resistance in ,which sense each wheel orroller is entirely independent of all others.

Having thusdescribed my invention, what I claim as new and desire tosecure by Letters Patent of the United States, is:

1. A driving mechanism embodying a flexible rack composed of a series oflinks pivotally connected on transverse axes intersecting thelongitudinal axis of the rack, saidlinks each having oppositely disposedtooth projections extending in opposite directions from the longitudinalcenter of the rack, and pairs of gear wheels arranged with the spacesbetween the wheels of each pair in alinement and the wheels of each pairbeing in mesh with the tooth projections on diametrically opposite sidesof the rack.

2. In a drivingmechanism, the combination with an endless flexible rackcomposed of a series of links pivotally connected on transverse axesintersecting the longitudinal axis of the rack, said, links eachembodying a plurality of oppositely disposed tooth projections extendingin opposite directions from the longitudinal center of the rack, a

supporting sheave on which said endless rack is suspended, and aplurality of pairs of gear wheels, the wheels of each pair meshing withthe diametrically opposite tooth projections on opposite sides of therack, said pairs of gear Wheels being arranged in alinement whereby thepower transmitting reach of the rack is maintained in substantially astraight line.

3. In a driving mechanism, the combination with an endless flexible rackembodying a series of links each formed with a plurality of oppositelydisposed tooth projections extending in opposite directions from thelongitudinal center of the rack, and edge links bridging the toothrecesses in alternate links on one side of the rack only, whereby thetooth recesses on the opposite side of the rack'a're left opentransversely of the rack, a supporting sheave with which the edge linkscooperate to support the rack in a pendent loop, and a plurality ofpairs of gear wheels meshing respectively with the diametricallyopposite tooth projections on mete Q opposite sides of the rack, theteeth of the gear Wheels on one side of the rack being confined betweenthe edge links.

4. An endless flexible rack embodying a series of links each having aplurality of diametrically oppositely disposed tooth projectionsextending in opposite directions from the longitudinal center of therack,

said links being pivotally connected together 10 on axes coincident withthe intersection of the tooth recesses on the opposite side of the 1rack being open.

FRANK H. VAN HOUTEN.

Witnesses:

J. M. VAN HoU'rnN, WILLIAM T. STRIPPEL.

